1. Standard for a Mixed-Signal Test Bus Top Level Architecture
IEEE
Standard for a Mixed-Signal Test Bus
Scope and Purpose
BSDL Extension
(2010 Revised Version)
Benefits
Defines a mixed-signal test bus architecture that provides access to analog and digital test points for:
Interconnect test
Parametric test
Internal test
Provides interconnect test for high-density surface-mount assembled boards.
Bridge and open faults detection test for both digital and analog nets can be performed simultaneously.
Passive analog components between chips are able to be measured.
Parametric test and internal analog test can also be performed.
BSDL extension allows mixed-signal chip vendors to provide description of their device’s test circuitry in the datasheet.
Third party tools will be able to generate interconnect test patterns automatically using the provided BSDL from each device.
Describes test circuitry in a device
Compatible with BSDL
To support test pattern generation process
Examples
Top Level Architecture
Description of boundary registers of an ABM
TMS
TDI
TDO
TCK
AT2
AT1
DIGITAL
I/O PINS
ANALOG
I/O PINS
TBIC (Test Bus
Interface Circuit)
Analog Test
Access Port
ATAP VH VL VG
Internal Test Bus
(AB1, AB2 )
Core
Circuit
Analog
Boundary
Module
(ABM)
Test Control Circuitry
TAP Controller
Instruction register and decoder
Digital Test
(TAP ) as in
IEEE
(TAP) as in
Scan Path
Digital
(DBM)
attribute BOUNDARY_REGISTER of comp_name : entity is
…..
“9 (BC_1, *, control, 0), ” & -- C
“8 (BC_7, A2, bidir, 0, 9, 0, Z), ” & -- D
“7 (BC_1, *, internal, 0), ” & -- B1
“6 (BC_1, *, internal, 0), ” & -- B2
Analog Boundary Module (ABM)
Core
VTH VH VL VG - +
SB2
SB1
AB1
AB2
Analog
function
pin
AT1
AT2 SD
disconnect
Internal analog
test bus
From TDI
To TDO SH SL SG
TBIC DS
ABM Switch Control
TBIC Statement
Potential Applications
Mixed-signal devices can be used in a system which is tested regularly in the field such as in safety critical applications.
Examples of safety critical applications include medical, security, transportation and process control.
Mixed-signal devices for commercial applications.
attribute MST_TBIC of comp_name : entity is
“ATI, AT2 : ” & -- pin1, pin2
“5, 4 ” & -- Ca, Co
“(IATB0 (3, 2), ” & -- D1a, D1b (Base)
“(IATB1 (1, 0) ” ; -- D2a, D2b (Partition)
Application Example
Extended interconnect test – measuring R value
ABM Statement
First measurement
Further Information
attribute MST_ABM of comp_name : entity is
-- port TBIC_partition_name C D B1 B2
“A1: IATB0 (13, 12, 11, 10), ” &
“A2: IATB1 (9, 8, 7, 6) ” ;
-- AB1a/AB2a from IATB0, AB1b/AB2b from IATB1
For further information, contact:
IEEE Mixed-Signal Test Bus Working Group at
Describing cells associated to each ABM
Second measurement
Present Working Group members:
Bambang Suparjo Heiko Ehrenberg Adam Cron
Stephen Sunter Kenneth P Parker Adam Ley
Keith Lofstrom Zafar Quadri Marc Hunter
attribute MST_ABM of CHIP_A : entity is
“A1 ( IATB0_A: 13, 12, 11, 10 ),” & -- C, D, B1, B2
Attribute MST_ABM of CHIP_B : entity is
“A5 ( IATB0_B: 8, 9, 10, 11 ),” & -- C, D, B1, B2
If Voltmeter impedance >> impedance of the switches
R = (VF1-VF2) / IT